This invention relates to a steel wire heat treatment apparatus. More particularly, this invention relates to a device for heat treating steel wire without the disadvantage of oxidation of the surface of the wire.
In a conventional heat treatment apparatus for steel wire which uses an electric furnace including a direct firing system or an indirect heating system, since there exists a space between a wire rod outlet of the electric furnace and a tempering oil tank, a wire rod leaving the electric furnace in a red-hot condition has oxides form on its surface upon contact with air, with the result that a thick and strong oxidation film is produced at the surface of the wire rod. Accordingly, it is necessary to remove such film by pickling or by other means in a succeeding process. If a heated wire rod having an oxidation film on its surface is immersed in tempering oil, difficulties as irregularity of quenching and scratching of the wire rod surface by oxide stuck thereto at a process after quenching will take place, with resultant deterioration of the quality of a processed wire rod. In addition, oxide will come off and stain the treating equipment.
The present invention provides a system to eliminate the above-mentioned defects of the conventional heat treatment apparatus for steel wire, and the primary object of the present invention is to prevent oxidation of a steel wire during a heat treatment.